1. Field of the Invention
The present invention relates to a high-strength landscape ring for the protection of tree trunks. The ring finds particular utility in lawn and garden maintenance programs.
2. Description of the Prior Art
It is known in the prior art to provide a cylindrical landscape ring about the trunk of a tree to protect the trunk from lawn maintenance equipment. One-piece cylindrical landscape rings typically comprise a cylindrical wall which employs a circumferential discontinuity to allow the ring to be deployed around the tree trunk. After deployment, the ring is closed using a connecting means.
In the past, landscape rings had insufficient strength to withstand the repeated and significant stresses likely to be encountered when the ring was kicked or hit by adults, playing children, animals, automobiles, and especially lawn-maintenance equipment such as lawnmowers and string-type trimmers. In addition, rings were circumferentially connected in the past using cumbersome, weak or unstable connecting mechanisms. Many of these mechanisms were characterized by low contact area resulting in low strength. Such connecting mechanisms may suffer from premature failure due to their tendency to fatigue, and eventually yield, when exposed to repeated cycles of installation and removal.
The latch system disclosed in U.S. Pat. No. 2,782,561 to Smith employs a projection which is inserted in a slot and bent downward to secure the closed ring. This system suffers from a lack of stability since the latch only secures the ring at its uppermost edge, leaving the lower portion of the ring subject to torque and breakage when the ring is moved or knocked by lawn maintenance equipment. In addition, the strength of the system is reduced because the connecting mechanism contact area is limited to a U-shaped projection at the upper portion of the ring. The system is also subject to failure due to fatigue since a projection such as that described is subject to yield after several cycles of being locked and unlocked.
The landscape ring disclosed in U.S. Pat. No. 2,909,328 to Babyak employs a connecting mechanism that comprises an essentially tubular coupling having a tubular male projection and a complementary female tubular receptor. Like the Smith mechanism, the Babyak mechanism secures the ring only at its uppermost portion, leaving the lower portion of the ring unlocked and subject to torque. In addition, the contact area in the Babyak mechanism is limited to the area shared between the male and female tubular projections.
Other prior art devices suffer similarly from low strength, low contact area, susceptibility to failure due to torque, susceptibility to yield after repeated use, and expense of manufacture. In still other devices, such as the tree trunk protector disclosed in Canadian Patent 2,041,694, the connecting mechanism employs "hook-like" prongs that are specifically designed to break if the protector is moved from the tree.
A need exists, therefore, for a high-strength landscape ring that employs a high-strength, high stability connecting mechanism that resists yield or loss of resilience after repeated use, installation and removal, that has a high contact area, that provides locking along the entire portion of the ring to minimize torque, and that is inexpensive to manufacture. Most advantageously, such a system would allow the homeowner to place the landscape ring around a tree, lock the ring for stability, strength, and a uniform appearance, and then subject it to routine shock and movement without compromising its connecting mechanism or stability.